MRT (Metropolitan Rapid Transit) is Bangkok rapid transit system, which is known as subway. Currently MRT provides service only one line (Blue line) which has 18 stations between Hua Lamphong and Bang Sue.
Phahon Yothin MRT station is a station that is located on Phahon Yothin Road, near Lat Phrao Intersection.
What to see around Phahon Yothin MRT Station
There are two big shopping malls around this station. Central Plaza Lad Phrao is just only 5-minute walk from the station. You can expect to see international brands, restaurants, coffee café, cinemas, and so on here.
Another shopping mall in the area is Union Mall. This mall is an indoor shopping mall where you can expect cheap products such as clothing, shoes, handbags, and accessories. This shopping mall is not that popular for tourists, but it is quite popular among locals who work or live in this area.
From the station, it is possible to walk to Vachirabenjatas Park (Suan Rot Fai), but I usually take metered-taxi. Besides, there is a place where we can learn dhamma, Suan Mokkh Bangkok (or Buddhadasa Indapanno Archives), located near the park. You can see my review of the park here.
Hope this information helps. Enjoy traveling Bangkok!